mission specialist's rex waldheim's 13th mission in space. >> i thought, am i going to get to the right before it closes or am i going to the very end? >> reporter: only one someone who has done it before can describe it like canadian astronaut chris hatfield who flew on atlantis previously. >> finally, the sky goes from light blue to dark blue to black and the engine shuts off and you are weightless. that's a great ride. >> reporter: just before beginning that ride, commander chris ferguson told mission control, we are completing a chapter in a journey that never end. the space shuttle is finishing but nasa's exploration of space is continuing. reporting live from the kennedy space center, i'm alan chernoff. >> reporter: big crowds gathered in oakland to watch that final shuttle launch. >> 4, 3, 2, 1. liftoff.